Degumming tobacco



Patented Nov. 5, 1940 PATENT OFFICE DEGUMJVHNG TOBACCO John M. Baer, Chicago, Ill., assignor to The Guardite Corporation, Chicago, Ill.

No Drawing. Application March 10, 1938, Serial No. 195,154

3 Claims.-

This invention relates to a method of degumming tobacco.

In the present procedure green tobacco is received at the factories in hogsheads containing 5 around 1,000 pounds of tobacco tightly packed. The so-called green tobacco is not actually green in color, but is the material which has been stored by the farmers in their warehouses and afterward sold and crated. The material has a large content of moisture frequently from to by weight and is quite pliable.

The surface of it, however, is coated with a thin gummy mass which sticks to the hands when the leaves are handled or touched and 15 makes manipulation of the tobacco extremely difficult and also causes everything that it comes in contact with to become sticky and gummy. This material is now universally sorted by hand and put through steam tunnels prior to stemming.

20 These steam tunnels fail to remove the gum, do

not heat the material uniformly and result in inadequate stemming operations. Particularly, an undesirably large amount of flagging occurs. A flag is a stem to which large sections of the g5 leaf still adhere after the stemming operation.

By means of the present invention the tobacco is handled more expeditiously, the gum is removed and the need of a steam tunnel is done away with and at the same time, the product produccd is more uniform and flagging is practically eliminated.

In accordance with this invention, green tobacco in the hogshead is placed in a vacuum chamber and subjected to a high vacuum suf- 5 ficient to cause a substantial drop in temperature of the contained tobacco, thereby Washing out the interstitial air by boiling of contained moisture in the tobacco. The tobacco is then steamed, preferably with superheated steam, as

40 for example, ordinary IOU-pound gauge pressure steam which has not been de-superheated. It has been discovered that treatment with the steam up to 130 F. for any normal period has no elfect upon the gum, but above 130 F., the gum disappears. This is particularly noticeable above 132 F., and a treatment to 140 F., without any holding period at this temperature will ordinarily insure complete removal. The temperature may be raised above 140 E, if desired, but inasmuch as the tobacco does not require the addition of moisture, the higher the temperature is raised,

the more moisture there is which will have to be removed.

It is therefore preferred to steam only to 140 F. after which the chamber may be evacuated again slightly, say, to lower the temperature to F. to E, steam again admitted to raise the temperature to F, and this repeated as often as desired. The tobacco is preferablyremoved at 140 F. and a suitable cycle is one in which the steaming operation is carried on four times. 5

The repetition of the steaming cycle is merely for uniformity throughout the hogshead and the number of operations required depends upon the non-uniformity of the tobacco, fewer operations being required for uniform tobacco.

The tobacco on removal is completely free from gum and is light and flufiy and easily handled and may be immediately stemmed. It is pre-' ferred immediately to unpack the material and pass it through suitable stemming machines. .15

Surprisingly enough, the lack of flagging in. the present process is especially interesting because of the increase in moisture content which occurs in the process. Normally, however, this increase is not much over 1 20 The tobacco prepared in this manner is normally used as smoking tobacco and is known as strips.

The foregoing detailed description is given for clearness of understanding only, and no unneces- 5 sary limitations should be understood therefrom.

I claim:

1. The method of treating green tobacco which comprises subjecting a hogshead of green tobacco to a high vacuum, removing non-condensible gas 30 substantially completely under such Vacuum, admitting steam to the hogshead to produce a temperature therein in excess of 130 F., cooling the product by subjecting to an increased vacuum, again steaming the product to a temperature in 35 excess of 130 F., repeating the cooling and steaming to produce a uniformly degummed green tobacco, and breaking the vacuum.

2. The method as set forth in claim 1 in which at least one of said steaming operations raises .40

the temperature throughout the tobacco to 140 3. The method of treating green tobacco hav-' ing a gummy deposit on the surface of the tobacco leaves, which comprises freeing the leaves substantially completely from non-condensible gasv and then condensing upon the surface there- 7 of steam from an atmosphere of steam at increased temperature, and introducing steam o thereto until the temperature of the tobacco has been raised by contact with the steam to at least 130 F. and until the gummy material has disappeared from the surface of the leaves, to produce a non-gummy tobacco of increased moisture con- 55 tent.

JOHN M. BAER. 

